Have you ever been on a plane during a thunderstorm that experienced a direct lightning strike? While most commercial airliner will do their best to avoid thunderclouds delivering the wrath of the atmosphere, it's estimated that every plane in the U.S. is struck more than once per year.

Large commercial planes are equipped to route the electrical current from a lightning strike so that it avoids sensitive electronics, and most passengers may not even realize that a plane has been struck when it does occur. However, the electrical current and loud clap of thunder are not all that is produced by a bolt of lightning. It's only within the past 20 years that research has confirmed that lightning also emits x-rays and gamma-rays.

One source of x-rays is normal lightning, under normal atmospheric pressure that occurs near the ground. These x-rays are measured at strengths analogous to the energy range commonly emitted by CT scanning devices used in the health care industry. Then there are gamma-rays, high energy x-rays usually seen emitted by particle accelerators, exploding stars, and black holes, that have been detected as a continuous kind of glow within clouds. Additionally, a separate class of gamma-rays, called terrestrial gamma-ray flashes or TGFs, are even more powerful, brief bursts that can be seen by spacecraft and satellites in low earth orbit. TGFs are the most energetic phenomena on the planet, and are thought to be caused by intracloud lightning (lightning that occurs between clouds). TGFs appear all over the world where there are thunderstorms, but nobody understands exactly why or how. Read the rest

The National Museum of Natural History's Sandra Raredon maintains the "fish library," a job that includes X-raying the specimens like this two-headed smooth-hound shark. Below, a small tooth sawfish and Atlantic angel shark.

What happens inside a caterpillar's cocoon? Scientists got to watch the whole process with the help of X-ray 3D scanning technology. In the video above, you can watch a caterpillar turn into a butterfly. Over the course of 16 days its breathing tubes (shown in blue) and its digestive system (shown in red) change shape and position within the body, while other structures grow from scratch.

Ed Yong has a great story to go with this, too. All about why it's important to actually watch the process happening in a single caterpillar, instead of just relying on the data scientists have collected from years of dissecting different caterpillars at different stages in the transformation. Read the rest

I dig this because, on verbal description, this sounds rather dull. X-rays of fishes. Great. But when you actually see the images you remember two very important facts: First, fishes have tons of little, teeny bones packed into a relatively small body; Second, fishes come in a wide variety of frequently crazy shapes. That all adds up to fish x-rays being way more interesting than you might initially guess.